Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

oxide7 writes "NASA is pushing the boundaries of technology as it readies its next mission to Mars, loading up its 4th Mars Rover with nearly a dozen instruments and deploying an innovative but risky landing procedure. Scientists and engineers were piecing together some of the final components to the new rover, dubbed Curiosity, on Saturday as it ramps up for a high-stakes launch in November."

If this method had a track record of success in some terrestrial application, then it would be new for a Mars mission, but would be perceived as less risky, because there would be less new science/design that would be required for it. Given that a rocket-powered skycrane has never been used over an extended period (at all?) in any terrestrial application, and that computer-controlled flying cranes are relatively new (anyone know of any deployed autonomous helicopter cranes?), it'

I think they'd prefer to go with airbags, but it's too heavy. My car doesn't weigh half that.. imagine hanging 2 cars from a "sky crane" powered by retros.. as it speeds towards the ground at 1000 mph. if one of the retros fails or the tether snaps, it's game over. compare that with: inflate bags @ a reasonable altitude and hope you don't hit a sharp rock.

NASA engineers and 'rocket scientists' have already determined that the 5 ton rover is too heavy for that method.

I think you misunderstand me. People fixate on Curiosity's skycrane, and think that it's new and overly complicated. It's not new. Everybody seems to forget that Spirit and Opportunity ALSO used a similar Parachute-Retrorocket-Tether system [youtube.com]. All they seem to remember is the airbag part of it. Spirit's and Opportunity's "skycranes" brought them to a hover in mid air and then cut them loose. They had to endure a drop equivalent to jumping off of a fourth floor balcony. This is why they needed the air bags.

In contrast, Curiosity's "skycrane" is going to lower it gently to the ground, not drop it from 50 feet in the air. There's much less risk involved with Curiosity's landing than Spirit's or Opportunity's. So, given that the MERs not only survived their riskier skycrane descent, and plummet to the ground, but thrived, odds are high that Curiosity will do the same.

Yes. There is a nice explanation at the Curiosity site (I think) that goes through the various thought processes but basically, IIRC

- The payload AND landing zone requirements made the rubber ball bouncing technique not viable- The unload off a ramp technique that the current rovers use doesn't scale well and has the major problem of failure if it lands on anything other than reasonably flat terrain. This limited the science and the landing site too much.- The retrorocket system has been used by Viking and the current rovers- The skycrane approach has a number of major advantages in terms of terrain avoidance, design of the rover, and size of payload at the expense of complexity.

The teams apparently felt that the risks were worth the benefits. Basically, they felt that unless the technology was pushed forward, the science packages would be too limited.

Or they could have reused the MER platform and these wouldn't have been issues in the first place. My view is that they are putting the cart before the horse with missions that have so many costly development hurdles.

No they could not. The MER (Mars Exploration Rover - Opportunity and Spirit) system can't land heavy payloads in a narrowly defined landing zone. Using that system, you get a landing ellipse of about 100 km2 area restricted to a band about 40 degrees above and below the equator (IIRC). For many, many interesting targets, that isn't good enough. You are also constrained to payloads about the same size as the baby rovers.

Yes, you can argue that the next step should be dozens of MER craft landed in many different zones. That is certainly a valid argument and one that has been made. However, according to the nice rocket scientists that have studied this for years (as opposed to us armchair astronauts who study things for 10 minutes max), it was felt that more significant research needed heavier payloads delivered with better accuracy.

I think there should be enough money in NASA's budget to fund both concepts (and Venus landers and Titan blimps and on and on) but I'm just a taxpayer.

The MER (Mars Exploration Rover - Opportunity and Spirit) system can't land heavy payloads in a narrowly defined landing zone.

And it's worth noting that NASA doesn't have a need to land in a narrowly defined landing zone, at least one much more narrowly defined than the MER were already capable of landing in.

That is certainly a valid argument and one that has been made. However, according to the nice rocket scientists that have studied this for years (as opposed to us armchair astronauts who study things for 10 minutes max), it was felt that more significant research needed heavier payloads delivered with better accuracy.

I would feel the "need" for a couple of billion dollars too. Keep in mind that this is a rover with a fair bit of range, allegedly more than the MERs. Further, its target is the Gale Crater, which, according to Wikipedia, is almost 100 miles in diameter. You don't need a pin-point landing.

As to "heavier instruments", It's worth noting that 8 or so MERs carry almost as much.

Finally, we have to consider both the degree of risk, namely, this is a riskier mission than one using a proven vehicle, and the concentration of risk, namely, the eggs are all in one vehicle. It matters because NASA, due to the way it structures space science missions, only has a few slots going to Mars. Any accident sets them back by years since they don't have another vehicle deployed which overlaps with the mission's goals or capabilities.

I don't need to be a rocket scientist to understand the problems with a mission approach.

And it's worth noting that NASA doesn't have a need to land in a narrowly defined landing zone, at least one much more narrowly defined than the MER were already capable of landing in.

Yeah, NASA doesn't know what they need...

Remember, Opportunity drove 20Mi/30km in 7 years. If you miss your target by 10km, that's a lot of time you'll need.

I would feel the "need" for a couple of billion dollars too. Keep in mind that this is a rover with a fair bit of range, allegedly more than the MERs. Further, its target is the Gale Crater, which, according to Wikipedia, is almost 100 miles in diameter. You don't need a pin-point landing.

See point above. And you want to target the rim of the crater usually. That's where the interesting geological formations are.

Finally, we have to consider both the degree of risk, namely, this is a riskier mission than one using a proven vehicle, and the concentration of risk, namely, the eggs are all in one vehicle. It matters because NASA, due to the way it structures space science missions, only has a few slots going to Mars. Any accident sets them back by years since they don't have another vehicle deployed which overlaps with the mission's goals or capabilities.

Of course, that's why they're testing Curiosity to death. No one wants to see it fail. But there's so much you can do with an existing vehicle. Maybe they could launch 8 MERs with different instruments, but it's probably more wor

Correction: You don't know what NASA needs. As I pointed out, it's a big crater, they don't need to be precise.

Remember, Opportunity drove 20Mi/30km in 7 years. If you miss your target by 10km, that's a lot of time you'll need.

No reason that a) they couldn't work on the delivery system for MER to be a bit more precise and b) no reason other than unfounded assertions from NASA that the MSL delivers any more precisely than a modified MER system would.

Of course, that's why they're testing Curiosity to death. No one wants to see it fail. But there's so much you can do with an existing vehicle. Maybe they could launch 8 MERs with different instruments, but it's probably more work than it's worth. Less risky, sure, but maybe not so scientifically groundbreaking.

I see that you completely miss the point. Existing vehicles need less testing. So sure, there's less you need to do with them! As to scientific output, I think observing eight

Tell that to NASA. It's clear you know jack shit a) the size of the crater, b) where they need to be

No reason that a) they couldn't work on the delivery system for MER to be a bit more precise and b) no reason other than unfounded assertions from NASA that the MSL delivers any more precisely than a modified MER system would.

Tell that to NASA. Or to the engineers that build it. Surely a./ commentator has more answers than them.

I'm not bothering with the rest f your post. You have really shown you can't comprehend written words and that it's pointless to discuss with you.

Tell that to NASA. It's clear you know jack shit a) the size of the crater, b) where they need to be

It's a bit late for that. However, I guess I need to point out that this is a game that NASA and other federal agencies have played for decades. They invent phony needs and get them funded. The discussion should have been from the beginning, how to get more for the money, not meeting some bogus "need" that someone cooked up in order to obtain more funding.

Tell that to NASA. Or to the engineers that build it. Surely a./ commentator has more answers than them.

Too late for that. We'll just have to see if the MSL works or not.

I'm not bothering with the rest f your post. You have really shown you can't comprehend written words and that it's pointless to discuss with you.

You could always just look at the past history of NASA and see for yourself. They had a

Sounds like the engineers fixed the problem. They could have just put the improvements on a MER vehicle rather than a MSL vehicle. I'm not advocating never changing a vehicle. But cautious modification of an existing vehicle will generally be less risky and have a shorter turnaround time than development of new vehicles.

I think there's little point to adding more instruments to a single vehicle. All you have to do is return a martian sample and then you have the instruments of the entire world, both present and future, to point at that location. No probe, no matter how loaded it is, can compete with that.

My view is that a two tier system of light-weight rovers, such as the MERs which already exist, combined with a considerable number of sample return missions will be much more effective for all practical purposes than t

Heck, I doubt you could land enough fuel in a 900kg payload to even reach martian orbit, and it's a whole lot further from there to earth

Actually, you could do it with a far smaller payload to Mars. The thing you need is sufficient mass fraction. There are probably sounding rockets on Earth which can fit in the above payload which can currently meet the minimum delta v for escape velocity from Mars. Then add in that you could extract propellant from the Martian atmosphere (meaning you eliminate the single biggest mass contribution to a return flight) and it's quite feasible with a 900 kg payload.

Since there was a lot of debate further on down the thread, I want to point out something important about the word "need" as it is used here. First, we don't need to explore Mars (even the intangibles which are often argued as being needed, such as inspiration to a generation of students, could be provided by cheaper, Earth-side sources). So fundamentally, there is no need.

Second, NASA has complete control over the design and operation of missions aside from funding authority which resides with Congress.

Airbags scale by a factor of ~2.5 with mass. MSL is much larger than the MERs. Thus it can't be landed with airbags and fit on top of a launch vehicle.

The skycrane, ridiculous as it may seem, is probably really the best way to get something the size of MSL to the ground. Whether or not they wouldn't have been better off selecting a couple of MER sized machines is a different question...

Why not deliver this rover the same way the other rovers were delivered?

They are delivering the rover the same way. They're just eliminating the "deploy the airbags and bounce around the planet for half an hour" part of the delivery, and are just placing the rover directly on the surface.

Because of its weight and sheer size, NASA cannot use the airbag padded rolling landing used for previous flights. Curiosity's landing will use a different method, lowering the rover on tethers from a rocket-backpack "sky crane."

Its too heavy for airbags. And the skycrane configuration has the advantage of a better view of thee terrain as it sets the rover down. Not to mention not kicking a bunch of crap up with retro rockets mounted on the rover and fouling its optics.

Piece of cake.This is an incredible approach at landing if it works everybody involved should and would feel proud of their work.

If it fails you'll never hear about it anymore.

Galileo Spacecraft it's never publicly mentioned in relation to the Shoemaker-Levy 9 impact on Jupiter.Yet it had a front roll seat, it watched the impacts, the fact it's high gain antenna wouldn't deploymeant it couldn't send pictures back.

I watched one of the Mars bots do it's beach ball landings, they keep saying "still rolling" un

However, in February 2009, because of the late delivery of several critical components and instruments, NASA delayed the launch to a date between October and December 2011.

This delay and the additional resources required to resolve the underlying technical issues increased the Project's development costs by 86 percent, from $969 million to the current $1.8 billion, and its life-cycle costs by 56 percent, from $1.6 billion to the current $2.5 billion.

So roughly two thirds of the cost of the entire mission is in developing the technology and building one vehicle. One thing that is routinely ignored in discussions of space probes is the trade-off between cutting edge development and actual output of the space probe. For example, instead of building the Mars Science Laboratory and its gear, we could have sent around 8 Mars Expedition Rovers (the actual cost of building and launching a rover is somewhere around $300 million). You might not h

All of the technology was new and unproven at some point. If you keep trying at it, it becomes less new and more tested. It's the nature of the game. Also, MER is not proven, it just happened to succeed twice. Don't get me wrong, they were excellent successes, but it's just 2 for 2.

Maybe you should brush up on basic statistics before calling others out on being wrong. It is feasible to have a experimental high success rate while having a low chance of individual success given that there are few enough trials. IOW you can't say with good certainty that any trial has a good success rate if you have too few previous trials to back it up, no matter their rate. TL;DR That's not proof.

Maybe you should brush up on basic statistics before calling others out on being wrong. It is feasible to have a experimental high success rate while having a low chance of individual success given that there are few enough trials. IOW you can't say with good certainty that any trial has a good success rate if you have too few previous trials to back it up, no matter their rate. TL;DR That's not proof.

There are two things to remark on here. First, context indicates that the successes are more significant than you'd expect statistically. It is rather unlikely for aerospace failures to be in a certain range of likelihood. Usually things either fail with certainty or have a rather high success rate (at least 50%). That's just a rule of thumb, but borne out by a lot of aerospace history. So even one success of a very difficult mission profile (such as landing on Mars and deploying a rover for several years)

One thing that is routinely ignored in discussions of space probes is the trade-off between cutting edge development and actual output of the space probe. For example, instead of building the Mars Science Laboratory and its gear, we could have sent around 8 Mars Expedition Rovers (the actual cost of building and launching a rover is somewhere around $300 million). You might not have gotten quite as nice a variety of scientific output for any given location as the MSL, but you'd get up to (counting the possi

IMHO, that is the point of NASA - to push the envelope of technological development in order to more rapidly create new innovative research methods and technologies, not to rest on its laurels and build a sustainable business model. The whole reason it's taxpayer-funded is because we expect lots of failures and for its returns to never directly pay for the initial investment. Bear in mind that NASA started off as NACA [wikipedia.org], whose goal was to centralize fundamental aerospace research. That way all companies could benefit from it, instead of each company wasting money conducting duplicate research to push the forefront of aviation. NACA itself didn't profit from its research.

The point here is who is going to use this stuff when NASA moves on? A similar though much shorter tech development stretch happened leading up to the Apollo launch.

In addition to the well-known manned aspect of Apollo and prior programs (Mercury and Gemini), we had several unmanned efforts including lunar orbiters and landers. In total, 21 unmanned space probes went to the Moon, to orbit it, collide with it, or gently land on it. While some of the unmanned stuff probably got used later on, it's still an

From the linked article: An instrument named ChemCam will use laser pulses to vaporize thin layers of material from Martian rocks or soil targets up to 7 meters (23 feet) away.

I have this mental image of thousands of tiny terrified martians fleeing their homes after the "heat ray" vaporizes the town square.

No-one would have believed, in the first years of the 21st century, that martian affairs were being watched from the timeless worlds of space. No one could have dreamed that we were being scrutinized as

Please tell me they have a way of getting dust off the solar panels. Every time I read about dust buildup on Spirit and Opportunity's solar panels causing problems all I could think of was why didn't they install some type of simple vibration mechanism or air jet or any number of possible solutions.

NASA has already explained this. It was not an oversight/mistake.The mission parameters only had a 90 day window.Why sacrifice weight, available space, and $$$ for features not needed for the job requirements.

It's not like software, where added features above requirements adds value at little, to no cost.In this case, added features have a sever penalty to the requirements.

I've been reading more about MSL in the last few hours and I see that it doesn't use solar panels. Good. Not removing dust from the MER's solar panels was a mistake in hindsight. No question. They designed for a 90 d mission, but the mission changed. If every system had started to fail at the 90 d mark it really would have sucked, and they'd use the same tired excuse of "but we designed strictly to the mission parameters." It costs a fortune to send these to Mars so longevity is crucial, and the power sourc

Please tell me they have a way of getting dust off the solar panels. Every time I read about dust buildup on Spirit and Opportunity's solar panels causing problems all I could think of was why didn't they install some type of simple vibration mechanism or air jet or any number of possible solutions.

Please tell me you have at least looked at the picture of the lander and realized it doesn't have any solar panels. Oh, wait, slap me. It's Slashdot....

So...why the fuck are we still shooting rovers to Mars? Why aren't we going ourselves yet? We've seen it, sampled it, measured and tested every aspect we can...it's time to pay the rock a fucking visit, not shoot more meters and probes at it.

Pull your heads out of your asses, government, and send a fucking human being to Mars already.

If by explore you mean that we've done the equivalent of exploring New York city by walking around LaGuardia airport. I guess the assumption is that Mars is pretty much the same terrain all over (excepting Olympus of course). I suspect this is not even close to true. Either way we aren't even close to the tech needed to send a human team to Mars (and back?).

Hey guys over at NASA, i hope you are reading this....here is what you needWINDSHIELD WIPERS.....to get the crap off the solar panels when it builds up......maybe add a special weight caliper that lets you know when some stuff is getting on the panel, then use the wiper to push it off......

seriously.....

also - please send another unit that has a) booster cables (for boosting the old one and getting back another rover)

The money is all spent here on earth. It goes for salaries, parts, labor, design, engineering, fuel. Those who get the money spend their earnings for groceries, gas, house payments, cars, shoes and junk food. Those suppliers do the same with there earnings. They hire lawn care "engineers" , painters, babysitters, oh, and they buy all of the above as well.

Somewhere along the line money gets to the burger flippers who could never understand economics 101, who post on Slashdot that everything they are not interested in is a waste of money.

I think the question is more one of "What do you get for the money you've spent?" A war sends men and material overseas and generally fewer come back than you sent; you might gain some political or diplomatic advantage, and that has to be judged against the cost. Space research sends men and rockets into space and generally fewer come back than you sent; you might gain some technological or scientific knowledge, and that has to be judged against the cost.

The money is all spent here on earth. It goes for salaries, parts, labor, design, engineering, fuel. Those who get the money spend their earnings for groceries, gas, house payments, cars, shoes and junk food. Those suppliers do the same with there earnings. They hire lawn care "engineers" , painters, babysitters, oh, and they buy all of the above as well.

Somewhere along the line money gets to the burger flippers who could never understand economics 101, who post on Slashdot that everything they are not interested in is a waste of money.

So why not just spend it all on me and cut out those middle men? I'll hire plenty of dudes so the employment angle is covered.

Well, that argument comes up because every single bloody time we spend some money on science, some dumb fuck inbred hick comes crawling out of the woods crying about how the ebil gubmint wastes the money it 'stole' from him by means of taxes. Oddly, the dumb fuck hicks never complain when said money is spent on wars against them ebil brown peoples.

I love the argument that the man is spending money elsewhere so it needs to be spent here too, its so circular

But that's not the argument, Osgeld.

With a mission to mars and these "cutting edge" technologies, there's at least a chance at something good, something really good coming out of it. The wars in Iraq and Afghanistan, not so much.

Plus, there's the possibility that frontiers give a people a useful goal besides getting rich and famous. Once Americans realized that there wasn't going to be any more "going West", there seemed to set in a sad narcissism that has manifested itself in some very self-destructive behavior, privately and publicly. Having a frontier again might not be such a bad thing. And since it only costs a fraction of what the Iraq and Afghanistan wars are costing, not to mention the thousands upon thousands of human lives that are wasted - flushed down the crapper - for no reason beyond putting cash into the pockets of military contractors, having a Martian frontier, no matter how far off the benefits might be (but there will certainly be benefits) doesn't seem like such a bad idea.

When I think about buying some new tech that might be useful to me, sometimes it helps to put its expense into perspective. And that perspective is often obtained through comparison with other things I spend money on. Like a new iPad is about the same cost as 20 bottles of Bombay gin. Or a Kurzweil PC3LE7 76 Key Semi weighted action Performance Controller & Workstation Keyboard is about the same cost as a trip to Vegas (rehab and course of penicillin not included).

And in the future, I'd prefer if you didn't start a comment with "I love the argument..." when you clearly don't love the argument at all. It's not even good sarcasm, it just makes you sound small. Of course, you can do what you like, but I'm just putting you on notice that this is your first strike.

With a mission to mars and these "cutting edge" technologies, there's at least a chance at something good, something really good coming out of it. The wars in Iraq and Afghanistan, not so much.

To the contrary, the wars in Iraq and Afghanistan have provided benefits to the US such as the weakening of Al Qaeda, state support for Al Qaeda, and the removal of a vicious dictator. In return, we have two more fairly stable democracies in the Middle East. It might not be worth the price, but that same consideration holds for a Mars rover.

To the contrary, the wars in Iraq and Afghanistan have provided benefits to the US such as the weakening of Al Qaeda, state support for Al Qaeda, and the removal of a vicious dictator.

Al Qaeda was never strong. In fact, there were NO Al Qaeda in Iraq before George W Bush invaded. Plus, there's zero evidence that Iraq ever was a "state sponsor" of Al Qaeda. And the removal of Saddam Hussein only served to make Iran a greater threat and by all accounts, nothing's gotten better in Iraq. They still don't h

It was strong enough to kill three thousand people in the US. It was strong enough that it has a cushy defense contract with the Taliban. They were working on developing nuclear and other weapons of mass destruction. You don't act merely on the basis of the present strength of the foe, but also on a realistic appraisal of their future strength.

And none of those things were worth the lives lost and the money spent. How many lives do you think will be lost sending rovers to Mars? The wars in Iraq and Afghanistan diminished us as a nation.

That's your opinion (not that you have shown any understanding of what strengthens or diminishes a country in the past). But the valuation isn't shared by everyone. A

Do you believe the wars in Iraq and Afghanistan made us safer from Al Qaeda?

Yes. Name an Al Qaeda attack on US soil since 9/11.

And you attribute the lack of Al Qaeda attacks on US soil since 9/11 to the war in Afghanistan?

Personally, I attribute it to the fact that God is keeping us safe just to thwart the fondest dreams of Republicans that there will be an attack during Barack Obama's presidency. It must be a great disappointment to them that Obama's been able to keep us safe when George Bush was not.

I'm sorry, friend, but I just can't talk to you about this subject any longer, since it's starting to depress me that there is actually an American voter who believes as you do. Until just now, I was pretty sure there were none.

I'm sorry, friend, but you've never been able to talk about this subject. Instead as in several other subjects, you've been able to babble irrationally about it such as the above post. Let's consider your statements:

And you attribute the lack of Al Qaeda attacks on US soil since 9/11 to the war in Afghanistan?

[...]

Personally, I attribute it to the fact that God is keeping us safe just to thwart the fondest dreams of Republicans that there will be an attack during Barack Obama's presidency. It must be a great disappointment to them that Obama's been able to keep us safe when George Bush was not.

Let's see here. We have not just a statement but a model. Suppose there is a paramilitary, "terrorist" organization with a power base in a country which openly supports the organization. Now, overthrow the country, wipe out the organization's power base there, and then kill off most of the

3)Build space elevator to atmosphere of Jupiter using asteroids for building material.

Even easier!!

5)Go anywhere you want after that because you've got fuel.

Any questions?

Sure:1) Where do you get all the dense mass to protect you from hard cosmic radiation?2) How do you protect the elevator from all that crap whizzing around Jupiter?3) What do you build the ship with?4) How do you provision it, etc, etc, etc?

The Earth and Sun just do too much that we take for granted, and stellar distances are just too great to be practical.

"1) Where do you get all the dense mass to protect you from hard cosmic radiation?2) How do you protect the elevator from all that crap whizzing around Jupiter?3) What do you build the ship with?4) How do you provision it, etc, etc, etc?"

1 - Congress. It seems that the members of congress are so dense that grinding them up and using them as radiation shielding will work better than anything else we have here on the planet.

1) Did you not realize that asteroids are largely "dense mass", aka 'rock'. Five meters of lunar regolith was found to be sufficient to not only guard against radiation in space, but actually provide a lower daily radiation dose than you would normally receive wandering around the surface of Earth.

2) You don't. You simply build your crawlers in such a manner that they continually rebuild the ribbon every pass.

3) An asteroid. You're already living in it, now you just have to figure out how to move i

Who comes up with these names? These generic names that are alleged to be primary characteristics of the capitalist are just frickin' lame. Left out of the pool are Greed, Disparity, Externality, Exploitation...

In other words, "Ambition", "Incentive", "Sacrifice", and "Reciprocity". Beats "stupidity". And before you ask, I'd rather have a martian probe called "Exploitation" than one called "Reciprocity".